Designs have been proposed for bar code decoding devices having picture taking functionality.
In U.S. Pat. No. 6,298,176, a picture taking bar code reading device is described that is equipped to output bar code data and associated image data. In one example described in U.S. Pat. No. 6,298,176, output image data is image data representing a handwritten signature. The image data output by the bar code decoding device may be subject to size correction, image orientation adjustment and image distortion correction image processing for correcting distortion resulting from an image being captured at an angle.
In U.S. Publication No. US2002/0171745, a picture taking bar code reading device is described which is in communication with a remote computer. The bar code reading device sends image data and associated bar code data to the remote computer. In one combined bar code/image data transmission scheme described in U.S. Publication No. US2002/0171745, an image data file in .PDF, .TIFF, or .BMP filed format is created at a data collection device which includes an image representation of a decoded bar code message and an image representation of the package including the bar code encoding the decoded message.
In U.S. Pat. No. 6,722,569 a picture taking bar code reading device is described that includes a color image sensor and a classification circuit which classifies image data as being either bi-tonal image data or color image data.
In U.S. Publication No. US2005/0001035 a picture taking bar code reading device is described which executes either a picture taking exposure control algorithm or bar code decoding exposure control algorithm depending on which mode is selected.
While the above references describe significant improvements in the art, there remains a need for improvement in the art of a picture taking optical reader which is capable of picture taking functionality and excellent bar code decoding functionality.
Performance of an optical reader may be hindered where an optical reader is operated to read bar code symbols or other indicia of a substrate having a “shiny” surface. Such substrates can include, e.g., metal, glass, and laminated plastic. Light rays emanating from a reader that are projected on a highly reflective shiny surface of a substrate may be substantially entirely reflected directly onto a reader image sensor array. Artisans skilled in the art of optical readers regard a “specular reflection” read condition to have occurred where a substantial percentage of light rays are reflected from a substrate and directed onto a reader image sensor array. Light rays are said to be reflected at a “specular” angle when light rays are reflected from a substrate at about the angle of incidence. Specular reflection tends to saturate a reader image sensor array to cause decoding failures. There is a need for an optical reader configured so that specular reflection read errors are reduced.